Vacuum adiabatic body and refrigerator

ABSTRACT

A vacuum adiabatic body includes a first plate, a second plate, a space between the first plate and the second plate configured to be a vacuum state, a support including at least a pair of support plates that maintain a distance between the first and second plates, and at least one radiation resistance sheet provided between the pair of support plates to reduce heat transfer between the first plate and the second plate.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/482,104, filed on Jul. 30, 2019, which is a U.S. National StageApplication under 35 U.S.C. § 371 of PCT Application No.PCT/KR2018/001385, filed Feb. 1, 2018, which claims priority to KoreanPatent Application No. 10-2017-0014981, filed Feb. 2, 2017, whose entiredisclosures are hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a vacuum adiabatic body and arefrigerator.

BACKGROUND ART

A vacuum adiabatic body is a product for suppressing heat transfer byvacuuming the interior of a body thereof. The vacuum adiabatic body mayreduce heat transfer by convection and conduction, and hence is appliedto heating apparatuses and refrigerating apparatuses. In a typicaladiabatic method applied to a refrigerator, although it is differentlyapplied in refrigeration and freezing, a foam urethane adiabatic wallhaving a thickness of about 30 cm or more is generally provided.However, the internal volume of the refrigerator is therefore reduced.

In order to increase the internal volume of a refrigerator, there is anattempt to apply a vacuum adiabatic body to the refrigerator.

First, Korean Patent No. 10-0343719 (Reference Document 1) of thepresent applicant has been disclosed. According to Reference Document 1,there is disclosed a method in which a vacuum adiabatic panel isprepared and then built in walls of a refrigerator, and the exterior ofthe vacuum adiabatic panel is finished with a separate molding asStyrofoam (polystyrene). According to the method, additional foaming isnot required, and the adiabatic performance of the refrigerator isimproved. However, fabrication cost is increased, and a fabricationmethod is complicated. As another example, a technique of providingwalls using a vacuum adiabatic material and additionally providingadiabatic walls using a foam filling material has been disclosed inKorean Patent Publication No. 10-2015-0012712 (Reference Document 2).According to Reference Document 2, fabrication cost is increased, and afabrication method is complicated.

As another example, there is an attempt to fabricate all walls of arefrigerator using a vacuum adiabatic body that is a single product. Forexample, a technique of providing an adiabatic structure of arefrigerator to be in a vacuum state has been disclosed in U.S. PatentLaid-Open Publication No. US2004226956A1 (Reference Document 3).However, it is difficult to obtain a practical level of an adiabaticeffect by providing a wall of the refrigerator with sufficient vacuum.In detail, there are limitations that it is difficult to prevent a heattransfer phenomenon at a contact portion between an outer case and aninner case having different temperatures, it is difficult to maintain astable vacuum state, and it is difficult to prevent deformation of acase due to a negative pressure of the vacuum state. Due to theselimitations, the technology disclosed in Reference Document 3 is limitedto a cryogenic refrigerator, and does not provide a level of technologyapplicable to general households.

DISCLOSURE Technical Problem

Embodiments provide a vacuum adiabatic body that is improved inadiabatic performance.

Technical Solution

In one embodiment, a vacuum adiabatic body includes a supporting unitincluding at least a pair of support plates to maintain a distance so atto maintain a vacuum space part and a heat resistance unit at leastincluding at least one radiation resistance sheet provided between thepair of support plates, wherein an edge of the radiation resistancesheet is disposed inside a virtual line directly connecting edges of thepair of support plates to each other. Thus, one radiation resistancesheet may prevent heat loss, which occurs when coming into contact withan external other part, from occurring. The radiation resistance sheetmay be a thin plate shape product and be deformable by an externalimpact to solve the above-described limitation.

When two or more radiation resistance sheets are provided, a spacingblock may be interposed in the spacing part between the radiationresistance sheets to block heat transfer between the sheets.

The pair of support plates may include a first support plate coming intocontact with the first plate member and a second support plate cominginto contact with the second plate member. Here, the second supportplate may have a size greater than that of the first support plate. Inthis case, the vacuum adiabatic body may be reinforced in strength tofirm a contact part of the second support plate.

The virtual line may be provided as an angle of about 45 degrees toimprove stability of the contact part between the supporting units andprevent adiabatic performance from being deteriorated due to contactbetween parts. Here, the angle of about 45 degrees may be defined as anangle that is inclined with respect to an extension direction of thesupporting unit.

The supporting unit may include: a first bar supporting the radiationresistance sheet; and a second bar which does not support the radiationresistance sheet. Thus, heat loss due to heat conduction that may occurbetween the radiation resistance sheet and the bar may be prevented. Inthe first bar, an entire inner circumferential surface of the first barmay not come into contact with the radiation resistance sheet. Forexample, the first bar and the radiation resistance sheet may come intocontact with each other only at an end of four corners of one radiationresistance sheet. The first bar may come into contact with the radiationresistance sheet due to a slight deformation of the radiation resistancesheet due to aging.

A distance from a supporting point at which the first bar supports theradiation resistance sheet to an edge of the radiation resistance sheetmay be less than that from the supporting point to the virtual line.Thus, even though the radiation resistance sheet is deformed, theradiation resistance may not pass through the virtual line to block theheat transfer between the radiation resistance sheets. The edge of theradiation resistance sheet may extend by a distance of about 10 mm toabout 15 mm from the supporting point.

The radiation resistance sheet may have emissivity less than that of theplate member to resist radiation heat transfer, thereby more improvingthe adiabatic performance.

In another embodiment, a refrigerator includes: a main body having aninternal space in which storage goods are stored and provided as avacuum adiabatic body; and a door provided to open/close the main bodyfrom an external space. Two or more supporting units coming into contactwith each other to maintain a vacuum space part. The supporting unit mayinclude: a first support plate supported by the first plate member; asecond support plate supported by the second plate member; and a barconnecting the first support plate to the second support plate. The barmay maintain a distance between the first support plate and the secondsupport plate, and an edge area of the radiation resistance sheet may bedisposed inside a virtual line connecting the first support plate to thesecond support plate with the shortest distance. Thus, even though theradiation resistance sheet is deformed, sealing performance of theradiation heat transfer may not be deteriorated.

An end of a side of one supporting unit may come into contact with thefirst support plate of the other supporting unit so as to be firmlymaintained at a contact point of each of the supporting units. An end ofa side of one supporting unit may include an end of the first supportplate of the one supporting unit and an end of the second support plate.The contact of the radiation resistance sheet of the supporting unitsmay be completely prevented.

An end of a side of one supporting unit may come into contact with anend of a side of the other supporting unit. The two or more supportingunits may come into contact with the same support plate. In this case,the supporting unit may be reinforced in strength by contact forcebetween the support plates.

In further another embodiment, in a vacuum adiabatic body, even though aradiation resistance sheet is deformed, an edge of the radiationresistance sheet may be disposed inside a straight line connecting edgesof the pair of support plates to each other, and a first hole into whichthe bar is inserted may be defined in the radiation resistance sheet.

To improve productivity of a product through temporary assembly of thesupport plate, the vacuum adiabatic body may further include: a seatingrib disposed on the support plate; and an insertion groove provided inthe radiation resistance sheet to allow the seating rib to passtherethrough. Here, the insertion groove may be provided in an edge ofthe radiation resistance sheet to prevent the radiation heat from havinga bad influence on the adiabatic function of the radiation resistancesheet.

At least two or more supporting units may be provided, and an end of onesupporting unit may come into contact with the first support plate ofthe other supporting unit to stably perform the supporting action of thetwo supporting unit.

Advantageous Effects

According to the embodiment, the adiabatic performance of the vacuumadiabatic body may be more improved.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a refrigerator according to anembodiment.

FIG. 2 is a view schematically illustrating a vacuum adiabatic body usedin a main body and a door of the refrigerator.

FIG. 3 is a view illustrating various embodiments of an internalconfiguration of a vacuum space part.

FIG. 4 is a view illustrating various embodiments of conductiveresistance sheets and peripheral portions thereof.

FIG. 5 is a view illustrating a state in which a radiation resistancesheet is coupled to a support unit.

FIG. 6 is a cross-sectional view taken along line I-I′ of FIG. 5.

FIG. 7 is a cross-sectional view taken along line II-II′ of FIG. 5.

FIG. 8 is a plan view illustrating one apex portion of the radiationresistance sheet.

FIGS. 9 to 12 are schematic cross-sectional views of a vacuum adiabaticbody into which the supporting unit is inserted.

FIG. 13 is schematic cross-sectional view of the supporting unit.

FIGS. 14 to 17 are schematic cross-sectional views of a vacuum adiabaticbody into which a supporting unit is inserted according to anotherembodiment.

FIG. 18 is schematic cross-sectional view of the supporting unitaccording to another embodiment.

FIG. 19 is an enlarged perspective view illustrating a contact part ofthe supporting unit.

FIG. 20 is a schematic view illustrating an edge part of the supportingunit.

FIGS. 21 to 24 are schematic cross-sectional views of a vacuum adiabaticbody into which a supporting unit is inserted according to furtheranother embodiment.

FIG. 25 is a graph illustrating a variation in adiabatic performance anda variation in gas conductivity according to a vacuum pressure byapplying a simulation.

FIG. 26 is a graph illustrating results obtained by observing a time anda pressure in a process of exhausting the inside of the vacuum adiabaticbody when a supporting unit is used.

FIG. 27 is a graph illustrating results obtained by comparing a vacuumpressure with gas conductivity.

BEST MODE

Hereinafter, exemplary embodiments will be described with reference tothe accompanying drawings. The invention may, however, be embodied inmany different forms and should not be construed as being limited to theembodiments set forth herein, and a person of ordinary skill in the art,who understands the spirit of the present invention, may readilyimplement other embodiments included within the scope of the sameconcept by adding, changing, deleting, and adding components; rather, itwill be understood that they are also included within the scope of thepresent invention.

The drawings shown below may be displayed differently from the actualproduct, or exaggerated or simple or detailed parts may be deleted, butthis is intended to facilitate understanding of the technical idea ofthe present invention. It should not be construed as limited.

In the following description, the term ‘vacuum pressure’ means a certainpressure state lower than atmospheric pressure. In addition, theexpression that a vacuum degree of A is higher than that of B means thata vacuum pressure of A is lower than that of B.

FIG. 1 is a perspective view of a refrigerator according to anembodiment.

Referring to FIG. 1, the refrigerator 1 includes a main body 2 providedwith a cavity 9 capable of storing storage goods and a door 3 providedto open/close the main body 2. The door 3 may be rotatably or movablydisposed to open/close the cavity 9. The cavity 9 may provide at leastone of a refrigerating chamber and a freezing chamber.

Parts constituting a freezing cycle in which cold air is supplied intothe cavity 9. Specifically, the parts include a compressor 4 forcompressing a refrigerant, a condenser 5 for condensing the compressedrefrigerant, an expander 6 for expanding the condensed refrigerant, andan evaporator 7 for evaporating the expanded refrigerant to take heat.As a typical structure, a fan may be installed at a position adjacent tothe evaporator 7, and a fluid blown from the fan may pass through theevaporator 7 and then be blown into the cavity 9. A freezing load iscontrolled by adjusting the blowing amount and blowing direction by thefan, adjusting the amount of a circulated refrigerant, or adjusting thecompression rate of the compressor, so that it is possible to control arefrigerating space or a freezing space.

FIG. 2 is a view schematically illustrating a vacuum adiabatic body usedin the main body and the door of the refrigerator. In FIG. 2, a mainbody-side vacuum adiabatic body is illustrated in a state in which topand side walls are removed, and a door-side vacuum adiabatic body isillustrated in a state in which a portion of a front wall is removed. Inaddition, sections of portions at conductive resistance sheets areprovided are schematically illustrated for convenience of understanding.

Referring to FIG. 2, the vacuum adiabatic body includes a first platemember (or first plate) 10 for providing a wall of a low-temperaturespace, a second plate member (or second plate) 20 for providing a wallof a high-temperature space, a vacuum space part (or vacuum space) 50defined as a gap part between the first and second plate members 10 and20. Also, the vacuum adiabatic body includes the conductive resistancesheets 60 and 63 for preventing heat conduction between the first andsecond plate members 10 and 20. A sealing part (or seal) 61 for sealingthe first and second plate members 10 and 20 is provided such that thevacuum space part 50 is in a sealing state. When the vacuum adiabaticbody is applied to a refrigerating or heating cabinet, the first platemember 10 may be referred to as an inner case, and the second platemember 20 may be referred to as an outer case. A machine chamber 8 inwhich parts providing a freezing cycle are accommodated is placed at alower rear side of the main body-side vacuum adiabatic body, and anexhaust port 40 for forming a vacuum state by exhausting air in thevacuum space part 50 is provided at any one side of the vacuum adiabaticbody. In addition, a conduit 64 passing through the vacuum space part 50may be further installed so as to install a defrosting water line andelectric lines.

The first plate member 10 may define at least one portion of a wall fora first space provided thereto. The second plate member 20 may define atleast one portion of a wall for a second space provided thereto. Thefirst space and the second space may be defined as spaces havingdifferent temperatures. Here, the wall for each space may serve as notonly a wall directly contacting the space but also a wall not contactingthe space. For example, the vacuum adiabatic body of the embodiment mayalso be applied to a product further having a separate wall contactingeach space.

Factors of heat transfer, which cause loss of the adiabatic effect ofthe vacuum adiabatic body, are heat conduction between the first andsecond plate members 10 and 20, heat radiation between the first andsecond plate members 10 and 20, and gas conduction of the vacuum spacepart 50.

Hereinafter, a heat resistance unit provided to reduce adiabatic lossrelated to the factors of the heat transfer will be provided. Meanwhile,the vacuum adiabatic body and the refrigerator of the embodiment do notexclude that another adiabatic means is further provided to at least oneside of the vacuum adiabatic body. Therefore, an adiabatic means usingfoaming or the like may be further provided to another side of thevacuum adiabatic body.

FIG. 3 is a view illustrating various embodiments of an internalconfiguration of the vacuum space part.

First, referring to FIG. 3a , the vacuum space part 50 is provided in athird space having a different pressure from the first and secondspaces, preferably, a vacuum state, thereby reducing adiabatic loss. Thethird space may be provided at a temperature between the temperature ofthe first space and the temperature of the second space. Since the thirdspace is provided as a space in the vacuum state, the first and secondplate members 10 and 20 receive a force contracting in a direction inwhich they approach each other due to a force corresponding to apressure difference between the first and second spaces. Therefore, thevacuum space part 50 may be deformed in a direction in which it isreduced. In this case, adiabatic loss may be caused due to an increasein amount of heat radiation, caused by the contraction of the vacuumspace part 50, and an increase in amount of heat conduction, caused bycontact between the plate members 10 and 20.

A supporting unit (or support) 30 may be provided to reduce thedeformation of the vacuum space part 50. The supporting unit 30 includesbars 31. The bars 31 may extend in a direction substantially vertical tothe first and second plate members 10 and 20 so as to support a distancebetween the first and second plate members 10 and 20. A support plate 35may be additionally provided to at least one end of the bar 31. Thesupport plate 35 connects at least two bars 31 to each other, and mayextend in a direction horizontal to the first and second plate members10 and 20. The support plate 35 may be provided in a plate shape, or maybe provided in a lattice shape such that its area contacting the firstor second plate member 10 or 20 is decreased, thereby reducing heattransfer. The bars 31 and the support plate 35 are fixed to each otherat at least one portion, to be inserted together between the first andsecond plate members 10 and 20. The support plate 35 contacts at leastone of the first and second plate members 10 and 20, thereby preventingdeformation of the first and second plate members 10 and 20. Inaddition, based on the extending direction of the bars 31, a totalsectional area of the support plate 35 is provided to be greater thanthat of the bars 31, so that heat transferred through the bars 31 may bediffused through the support plate 35.

A material of the supporting unit 30 may include a resin selected fromthe group consisting of PC, glass fiber PC, low outgassing PC, PPS, andLCP so as to obtain high compressive strength, low outgassing and waterabsorption, low thermal conductivity, high compressive strength at hightemperature, and excellent machinability.

A radiation resistance sheet 32 for reducing heat radiation between thefirst and second plate members 10 and 20 through the vacuum space part50 will be described. The first and second plate members 10 and 20 maybe made of a stainless material capable of preventing corrosion andproviding a sufficient strength. The stainless material has a relativelyhigh emissivity of 0.16, and hence a large amount of radiation heat maybe transferred. In addition, the supporting unit 30 made of the resinhas a lower emissivity than the plate members, and is not entirelyprovided to inner surfaces of the first and second plate members 10 and20. Hence, the supporting unit 30 does not have great influence onradiation heat. Therefore, the radiation resistance sheet 32 may beprovided in a plate shape over a majority of the area of the vacuumspace part 50 so as to concentrate on reduction of radiation heattransferred between the first and second plate members 10 and 20. Aproduct having a low emissivity may be preferably used as the materialof the radiation resistance sheet 32. In an embodiment, an aluminum foilhaving an emissivity of 0.02 may be used as the radiation resistancesheet 32. Since the transfer of radiation heat cannot be sufficientlyblocked using one radiation resistance sheet, at least two radiationresistance sheets 32 may be provided at a certain distance so as not tocontact each other. In addition, at least one radiation resistance sheetmay be provided in a state in which it contacts the inner surface of thefirst or second plate member 10 or 20.

Referring to FIG. 3b , the distance between the plate members ismaintained by the supporting unit 30, and a porous substance 33 may befilled in the vacuum space part 50. The porous substance 33 may have ahigher emissivity than the stainless material of the first and secondplate members 10 and 20. However, since the porous substance 33 isfilled in the vacuum space part 50, the porous substance 33 has a highefficiency for resisting the radiation heat transfer.

In this embodiment, the vacuum adiabatic body may be fabricated withoutusing the radiation resistance sheet 32.

Referring to FIG. 3c , the supporting unit 30 maintaining the vacuumspace part 50 is not provided. Instead of the supporting unit 30, theporous substance 33 is provided in a state in which it is surrounded bya film 34. In this case, the porous substance 33 may be provided in astate in which it is compressed so as to maintain the gap of the vacuumspace part 50. The film 34 is made of, for example, a PE material, andmay be provided in a state in which holes are formed therein.

In this embodiment, the vacuum adiabatic body may be fabricated withoutusing the supporting unit 30. In other words, the porous substance 33may simultaneously serve as the radiation resistance sheet 32 and thesupporting unit 30.

FIG. 4 is a view showing various embodiments of the conductiveresistance sheets and peripheral parts thereof. Structures of theconductive resistance sheets are briefly illustrated in FIG. 2, but willbe understood in detail with reference to FIG. 4.

First, a conductive resistance sheet proposed in FIG. 4a may bepreferably applied to the main body-side vacuum adiabatic body.Specifically, the first and second plate members 10 and 20 are to besealed so as to vacuum the interior of the vacuum adiabatic body. Inthis case, since the two plate members have different temperatures fromeach other, heat transfer may occur between the two plate members. Aconductive resistance sheet 60 is provided to prevent heat conductionbetween two different kinds of plate members.

The conductive resistance sheet 60 may be provided with sealing parts 61at which both ends of the conductive resistance sheet 60 are sealed todefining at least one portion of the wall for the third space andmaintain the vacuum state. The conductive resistance sheet 60 may beprovided as a thin foil in unit of micrometer so as to reduce the amountof heat conducted along the wall for the third space. The sealing parts61 may be provided as a welding part. That is, the conductive resistancesheet 60 and the plate members 10 and 20 may be fused to each other. Inorder to cause a fusing action between the conductive resistance sheet60 and the plate members 10 and 20, the conductive resistance sheet 60and the plate members 10 and 20 may be made of the same material, and astainless material may be used as the material. The sealing parts 61 arenot limited to the welding parts, and may be provided through a processsuch as cocking. The conductive resistance sheet 60 may be provided in acurved shape. Thus, a heat conduction distance of the conductiveresistance sheet 60 is provided longer than the linear distance of eachplate member, so that the amount of heat conduction may be furtherreduced.

A change in temperature occurs along the conductive resistance sheet 60.Therefore, in order to block heat transfer to the exterior of theconductive resistance sheet 60, a shielding part (or shield) 62 may beprovided at the exterior of the conductive resistance sheet 60 such thatan adiabatic action occurs. In other words, in the refrigerator, thesecond plate member 20 has a high temperature and the first plate member10 has a low temperature. In addition, heat conduction from hightemperature to low temperature occurs in the conductive resistance sheet60, and hence the temperature of the conductive resistance sheet 60 issuddenly changed. Therefore, when the conductive resistance sheet 60 isopened to the exterior thereof, heat transfer through the opened placemay seriously occur. In order to reduce heat loss, the shielding part 62is provided at the exterior of the conductive resistance sheet 60. Forexample, when the conductive resistance sheet 60 is exposed to any oneof the low-temperature space and the high-temperature space, theconductive resistance sheet 60 does not serve as a conductive resistoras well as the exposed portion thereof, which is not preferable.

The shielding part 62 may be provided as a porous substance contactingan outer surface of the conductive resistance sheet 60. The shieldingpart 62 may be provided as an adiabatic structure, e.g., a separategasket, which is placed at the exterior of the conductive resistancesheet 60. The shielding part 62 may be provided as a portion of thevacuum adiabatic body, which is provided at a position facing acorresponding conductive resistance sheet 60 when the main body-sidevacuum adiabatic body is closed with respect to the door-side vacuumadiabatic body. In order to reduce heat loss even when the main body andthe door are opened, the shielding part 62 may be preferably provided asa porous substance or a separate adiabatic structure.

A conductive resistance sheet proposed in FIG. 4b may be preferablyapplied to the door-side vacuum adiabatic body. In FIG. 4b , portionsdifferent from those of FIG. 4a are described in detail, and the samedescription is applied to portions identical to those of FIG. 4a . Aside frame 70 is further provided at an outside of the conductiveresistance sheet 60. A part for sealing between the door and the mainbody, an exhaust port necessary for an exhaust process, a getter port(or vacuum port) for vacuum maintenance, and the like may be placed onthe side frame 70. This is because the mounting of parts is convenientin the main body-side vacuum adiabatic body, but the mounting positionsof parts are limited in the door-side vacuum adiabatic body.

In the door-side vacuum adiabatic body, it is difficult to place theconductive resistance sheet 60 at a front end portion of the vacuumspace part, i.e., a corner side portion of the vacuum space part. Thisis because, unlike the main body, a corner edge portion of the door isexposed to the exterior. More specifically, if the conductive resistancesheet 60 is placed at the front end portion of the vacuum space part,the corner edge portion of the door is exposed to the exterior, andhence there is a disadvantage in that a separate adiabatic part shouldbe configured so as to heat-insulate the conductive resistance sheet 60.

A conductive resistance sheet proposed in FIG. 4c may be preferablyinstalled in the conduit passing through the vacuum space part. In FIG.4c , portions different from those of FIGS. 4a and 4b are described indetail, and the same description is applied to portions identical tothose of FIGS. 4a and 4b . A conductive resistance sheet having the sameshape as that of FIG. 4a , preferably, a wrinkled conductive resistancesheet 63 may be provided at a peripheral portion of the conduit 64.Accordingly, a heat transfer path may be lengthened, and deformationcaused by a pressure difference may be prevented. In addition, aseparate shielding part may be provided to improve the adiabaticperformance of the conductive resistance sheet.

A heat transfer path between the first and second plate members 10 and20 will be described with reference back to FIG. 4a . Heat passingthrough the vacuum adiabatic body may be divided into surface conductionheat {circle around (1)} conducted along a surface of the vacuumadiabatic body, more specifically, the conductive resistance sheet 60,supporter conduction heat {circle around (2)} conducted along thesupporting unit 30 provided inside the vacuum adiabatic body, gasconduction heat {circle around (3)} conducted through an internal gas inthe vacuum space part, and radiation transfer heat {circle around (4)}transferred through the vacuum space part.

The transfer heat may be changed depending on various depending onvarious design dimensions. For example, the supporting unit may bechanged such that the first and second plate members 10 and 20 mayendure a vacuum pressure without being deformed, the vacuum pressure maybe changed, the distance between the plate members may be changed, andthe length of the conductive resistance sheet may be changed. Thetransfer heat may be changed depending on a difference in temperaturebetween the spaces (the first and second spaces) respectively providedby the plate members. In the embodiment, a preferred configuration ofthe vacuum adiabatic body has been found by considering that its totalheat transfer amount is smaller than that of a typical adiabaticstructure formed by foaming polyurethane. In a typical refrigeratorincluding the adiabatic structure formed by foaming the polyurethane, aneffective heat transfer coefficient may be proposed as 19.6 mW/mK.

By performing a relative analysis on heat transfer amounts of the vacuumadiabatic body of the embodiment, a heat transfer amount by the gasconduction heat {circle around (3)} may become smallest. For example,the heat transfer amount by the gas conduction heat {circle around (3)}may be controlled to be equal to or smaller than 4% of the total heattransfer amount. A heat transfer amount by solid conduction heat definedas a sum of the surface conduction heat {circle around (1)} and thesupporter conduction heat {circle around (2)} is largest. For example,the heat transfer amount by the solid conduction heat may reach 75% ofthe total heat transfer amount. A heat transfer amount by the radiationtransfer heat {circle around (4)} is smaller than the heat transferamount by the solid conduction heat but larger than the heat transferamount of the gas conduction heat {circle around (3)}. For example, theheat transfer amount by the radiation transfer heat {circle around (4)}may occupy about 20% of the total heat transfer amount.

According to such a heat transfer distribution, effective heat transfercoefficients (eK: effective K) (W/mK) of the surface conduction heat{circle around (1)}, the supporter conduction heat {circle around (2)},the gas conduction heat {circle around (3)}, and the radiation transferheat {circle around (4)} may have an order of Math Formula 1.eK solid conduction heat>eK radiation transfer heat>eK gas conductionheat  Math FIG. 1

Here, the effective heat transfer coefficient (eK) is a value that maybe measured using a shape and temperature differences of a targetproduct. The effective heat transfer coefficient (eK) is a value thatmay be obtained by measuring a total heat transfer amount and atemperature at least one portion at which heat is transferred. Forexample, a calorific value (W) is measured using a heating source thatmay be quantitatively measured in the refrigerator, a temperaturedistribution (K) of the door is measured using heats respectivelytransferred through a main body and an edge of the door of therefrigerator, and a path through which heat is transferred is calculatedas a conversion value (m), thereby evaluating an effective heat transfercoefficient.

The effective heat transfer coefficient (eK) of the entire vacuumadiabatic body is a value given by k=QL/AΔT. Here, Q denotes a calorificvalue (W) and may be obtained using a calorific value of a heater. Adenotes a sectional area (m2) of the vacuum adiabatic body, L denotes athickness (m) of the vacuum adiabatic body, and ΔT denotes a temperaturedifference.

For the surface conduction heat, a conductive calorific value may beobtained through a temperature difference (ΔT) between an entrance andan exit of the conductive resistance sheet 60 or 63, a sectional area(A) of the conductive resistance sheet, a length (L) of the conductiveresistance sheet, and a thermal conductivity (k) of the conductiveresistance sheet (the thermal conductivity of the conductive resistancesheet is a material property of a material and may be obtained inadvance). For the supporter conduction heat, a conductive calorificvalue may be obtained through a temperature difference (ΔT) between anentrance and an exit of the supporting unit 30, a sectional area (A) ofthe supporting unit, a length (L) of the supporting unit, and a thermalconductivity (k) of the supporting unit. Here, the thermal conductivityof the supporting unit is a material property of a material and may beobtained in advance. The sum of the gas conduction heat {circle around(3)}, and the radiation transfer heat {circle around (4)} may beobtained by subtracting the surface conduction heat and the supporterconduction heat from the heat transfer amount of the entire vacuumadiabatic body. A ratio of the gas conduction heat {circle around (3)},and the radiation transfer heat {circle around (4)} may be obtained byevaluating radiation transfer heat when no gas conduction heat exists byremarkably lowering a vacuum degree of the vacuum space part 50.

When a porous substance is provided inside the vacuum space part 50,porous substance conduction heat {circle around (5)} may be a sum of thesupporter conduction heat {circle around (2)} and the radiation transferheat {circle around (4)}. The porous substance conduction heat {circlearound (5)} may be changed depending on various variables including akind, an amount, and the like of the porous substance.

According to an embodiment, a temperature difference ΔT1 between ageometric center formed by adjacent bars 31 and a point at which each ofthe bars 31 is located may be preferably provided to be less than 0.5°C. Also, a temperature difference ΔT2 between the geometric centerformed by the adjacent bars 31 and an edge portion of the vacuumadiabatic body may be preferably provided to be less than 0.5° C. In thesecond plate member 20, a temperature difference between an averagetemperature of the second plate and a temperature at a point at which aheat transfer path passing through the conductive resistance sheet 60 or63 meets the second plate may be largest. For example, when the secondspace is a region hotter than the first space, the temperature at thepoint at which the heat transfer path passing through the conductiveresistance sheet meets the second plate member becomes lowest.Similarly, when the second space is a region colder than the firstspace, the temperature at the point at which the heat transfer pathpassing through the conductive resistance sheet meets the second platemember becomes highest.

This means that the amount of heat transferred through other pointsexcept the surface conduction heat passing through the conductiveresistance sheet should be controlled, and the entire heat transferamount satisfying the vacuum adiabatic body may be achieved only whenthe surface conduction heat occupies the largest heat transfer amount.To this end, a temperature variation of the conductive resistance sheetmay be controlled to be larger than that of the plate member.

Physical characteristics of the parts constituting the vacuum adiabaticbody will be described. In the vacuum adiabatic body, a force by vacuumpressure is applied to all of the parts. Therefore, a material havingstrength (N/m2) of a certain level may be preferably used.

Under such circumferences, the plate members 10 and 20 and the sideframe 70 may be preferably made of a material having a sufficientstrength with which they are not damaged by even vacuum pressure. Forexample, when the number of bars 31 is decreased so as to limit thesupport conduction heat, deformation of the plate member occurs due tothe vacuum pressure, which may bad influence on the external appearanceof refrigerator. The radiation resistance sheet 32 may be preferablymade of a material that has a low emissivity and may be easily subjectedto thin film processing. Also, the radiation resistance sheet 32 is toensure strength enough not to be deformed by an external impact. Thesupporting unit 30 is provided with strength enough to support the forceby the vacuum pressure and endure an external impact, and is to havemachinability. The conductive resistance sheet 60 may be preferably madeof a material that has a thin plate shape and may endure the vacuumpressure.

In an embodiment, the plate member, the side frame, and the conductiveresistance sheet may be made of stainless materials having the samestrength. The radiation resistance sheet may be made of aluminum havinga weaker strength that the stainless materials. The supporting unit maybe made of resin having a weaker strength than the aluminum.

Unlike the strength from the point of view of materials, analysis fromthe point of view of stiffness is required. The stiffness (N/m) is aproperty that would not be easily deformed. Although the same materialis used, its stiffness may be changed depending on its shape. Theconductive resistance sheets 60 or 63 may be made of a material havingstrength, but the stiffness of the material is preferably low so as toincrease heat resistance and minimize radiation heat as the conductiveresistance sheet is uniformly spread without any roughness when thevacuum pressure is applied. The radiation resistance sheet 32 requires astiffness of a certain level so as not to contact another part due todeformation. Particularly, an edge portion of the radiation resistancesheet may generate conduction heat due to drooping caused by theself-load of the radiation resistance sheet. Therefore, a stiffness of acertain level is required. The supporting unit 30 requires stiffnessenough to endure a compressive stress from the plate member and anexternal impact.

In an embodiment, the plate member and the side frame may preferablyhave the highest stiffness so as to prevent deformation caused by thevacuum pressure. The supporting unit, particularly, the bar maypreferably have the second highest stiffness. The radiation resistancesheet may preferably have a stiffness that is lower than that of thesupporting unit but higher than that of the conductive resistance sheet.The conductive resistance sheet may be preferably made of a materialthat is easily deformed by the vacuum pressure and has the loweststiffness.

Even when the porous substance 33 is filled in the vacuum space part 50,the conductive resistance sheet may preferably have the loweststiffness, and the plate member and the side frame may preferably havethe highest stiffness.

FIG. 5 is a view illustrating a state in which a radiation resistancesheet is coupled to a support unit.

Referring to FIG. 5, a radiation resistance sheet 32 is located insidethe vacuum space part 50 by fitting a bar 31 into a hole 38 defined inthe radiation resistance sheet 32. The hole 38 and the bar 31 may bespaced a predetermined distance from each other. The bar 31 may performa fixing function of the radiation resistance sheet 32 and maintain thedistance with the vacuum space part 50. That is to say, when the bar 31extends to maintain the distance between the plate members, the barpasses through the radiation resistance sheet 32. Here, the hole 38 forpreventing an interference with the radiation resistance sheet 32 has tobe provided. Here, the bar 31 may be provided to be integrated with thesupport plate 35.

Also, to perform sufficient radiation resistance action, at least tworadiation resistance sheets, preferably, three or more radiationresistance sheets 32 may be provided. To sufficiently realize theradiation resistance effect by using the plurality of radiationresistance sheets 321, 322, and 333, the inside of the vacuum space part50 may be equally divided, and the plurality of radiation resistancesheets may be respectively disposed in the divided spaces. That is, adistance between the radiation resistance sheets may be sufficientlymaintained to be spaced apart from each other. For this, a spacing block36 for spacing the plate members 10 and 20 from the radiation resistancesheets and spacing the radiation resistance sheets from each other maybe provided.

A seating rib 384 may be provided to temporarily couple the supportplates to each other or coupling the supporting unit to the first platemember 10. Also, an insertion groove 383 is defined in an edge of theradiation resistance sheet 32 to prevent the seating rib 384 frominterfering with the radiation resistance sheet 32. Since the seatingrib 384 is inserted through the insertion groove 383, the radiationresistance sheet 32 may be expanded outward and more stably resistradiation heat transfer.

FIG. 6 is a cross-sectional view taken along line I-I′ of FIG. 5, andFIG. 7 is a cross-sectional view taken along line II-II′ of FIG. 5.Here, FIG. 6 is a cross-sectional view of a first hole 382 through whichthe bar 31 passes to support the radiation resistance sheet 32 and aperipheral portion thereof, and FIG. 7 is a cross-sectional view of asecond hole 381 through which the bar 31 passes without supporting theradiation resistance sheet 32 and a peripheral portion thereof.

Referring to FIG. 6, the radiation resistance sheets 321, 322, and 333in which the first hole 382 is defined and the bar 31 passing throughthe first hole 382 are illustrated. Also, the spacing blocks 361, 362,and 363 may be provided to maintain the distance between the radiationresistance sheets and the distance between the radiation resistancesheet and the support plate 35. The first hole 382 may have a diameterso that only a predetermined assembly tolerance is included in adiameter of the bar 31 to guide a position of the radiation resistancesheet with respect to the bar 31. If the first hole 382 has a too smalldiameter, it may be difficult to fit the radiation resistance sheet 32into the bar 31, and thus, the thin radiation resistance sheet 32 may bedamaged during the process. Thus, the diameter of the first hole 382 hasto be provided to further reflect a length of the assembly tolerance. Onthe other hand, if the first hole 382 has a too large diameter,vibration may occur even though the radiation resistance sheet 32 issupported by the bar 31, and thus, the radiation resistance sheet 32 maybe deformed. Thus, the diameter of the first hole 382 has to be providedto further reflect a length of only the assembly tolerance. In thissituation, the inventor has found that it is desirable to provide theassembly tolerance in a range of about 0.1 mm to about 0.5 mm. In FIG.6, the sum of W3 on both sides of the bar is considered as an assemblytolerance.

When the first hole 382 is defined, it is preferable that no portion ofthe radiation resistance sheet 32 comes into contact with the bar 31.This is because when the radiation resistance sheet 32 comes intocontact with the bar, heat conduction may be generated to deteriorate anadiabatic effect. It may be desirable to support the plurality of firstholes 382 at as few positions as possible due to the interaction of theplurality of first holes 382.

Referring to FIG. 7, the radiation resistance sheets 321, 322, and 333in which the second hole 381 is defined and the bar 31 passing throughthe second hole 381 are illustrated.

When the second hole 381 has a too large diameter, the radiationresistance sheet 32 may comes into contact with the bar 31 to cause anadiabatic loss. If the second hole 381 has a too large diameter,radiation heat loss may occur through the spacing part between the bar31 and the second hole 381. In this situation, the inventor has foundthat the sum of both spaces between the second hole 381 and the bar 31is provided in range of about 0.3 mm to about 1.5 mm. In FIG. 8, a valueof the sum of W4 on both sides of the bar corresponds thereto.

A bar inserted into the first hole 382 to support a horizontal movementof the radiation resistance sheet may be referred to as a first bar, anda bar inserted into the second hole 381 without supporting thehorizontal movement of the radiation resistance sheet may be referred toas a second bar.

The spacing block 36 may is greater than any of the holes 381 and 382 sothat the spacing block 36 does not interfere with the space maintenanceof the radiation resistance sheet 32.

FIG. 8 is a plan view illustrating one apex portion of the radiationresistance sheet.

Referring to FIG. 8, the first hole 382 having a small diameter and thesecond hole 381 having a diameter greater than that of the first hole382 are processed in the radiation resistance sheet 32. There has beendescribed the passing function of the bar 31 through the holes 381 and382 and the supporting function of the radiation resistance sheet 32.

The first holes 382 may be provided as closely as possible to preventthe radiation resistance sheet 32 from being shaken. However, since themore the number of first holes 382 increases, the more contact portionsor approaching portions between the radiation resistance sheet 32 andthe bar 31 increase, the adiabatic performance may be deteriorated.Considering the above-described two conditions, it is preferable thatthe distance between the first holes 382 does not exceed a maximum of200 mm when the radiation resistance sheet is an aluminum foil having athickness of about 0.3 mm. In the case in which a cross-section of thedoor 3 is provided with a curved line, since the radiation resistancesheet is also provided as a curved surface, the distance between thefirst holes 382 may need to be further maintained so as to avoid thecontact between the radiation resistance sheets.

According to this background, it is preferable that W5 indicated by thedistance between the first holes 382 does not exceed a maximum of about200 mm. Also, it is preferable that the first hole 382 is provided atthe outermost portion, i.e., a vertex portion with respect to a centerof the radiation resistance sheet 32. This is for the purpose ofpreventing deterioration of the adiabatic performance due to the contactbetween the radiation resistance sheet 32 and the bar 31 and the purposeof allowing the radiation resistance sheet 32 to extend as much aspossible to prevent deterioration of the heat insulating performance.Also, three second holes 381 may be defined between a pair of firstholes 382 that are directly adjacent to each other. Also, to prevent theadiabatic performance from being deteriorated, in any one radiationresistance sheet, the number of first holes 382 may be less than that ofsecond holes 381.

Since the radiation resistance sheet 32 is provided as the foil, theradiation resistance sheet 32 may be deformed by an external impact.When the radiation resistance sheet 32 is deformed to come into contactwith other parts within the vacuum space part 50, heat conductionperformance may increase to deteriorate the adiabatic performance of thevacuum adiabatic body. In addition, the contact 32 between the radiationresistance sheets promotes the heat conduction between the sheets anddoes not resist the radiation heat transfer of the radiation resistancesheet.

An inner area of a two-dimensional entire area of the radiationresistance sheet 32 may stop the horizontal movement by the mutualsupport action of the bar 31 and the first hole 382, and the verticalmovement may be stopped by mutual support between the radiationresistance sheets 32 by the spacing blocks 361, 362, and 363.

An outer area, that is, an edge area, of an entire two-dimensional areaof the radiation resistance sheet 32 may be an area that is notsupported by the bar 31, the first hole 382, and the spacing blocks 361,362, and 363, and thus, the area may freely move. The edge area maydefine a position where the first hole 382 and the spacing blocks 361,362, and 363 are formed horizontally and outwardly. Alternatively, sincethe first hole and the spacing block have a certain level of an error,it is not possible to strictly define the edge area, but it may beinterpreted within a range of engineering error.

Since the edge area exists, that the outer area of the radiationresistance sheet 32 is prevented from coming into contact with otherparts of the vacuum space portion 50 and that the outer area of theradiation resistance sheet 32 does not come into contact with theradiation resistance sheet 32 may act as a major one factor in improvingthe adiabatic performance of the vacuum adiabatic body.

The supporting unit 30 may be applied to both the door 3 and a main body2. In the supporting unit 30 inserted into the vacuum space part 50 ofthe main body 2, the supporting units inserted into different planes maycome into contact with each other unlike the supporting unit 30 insertedinto the door 3. In this case, the supporting units 30 may come intocontact with each other, and when the supporting units 30 comes intocontact with each other, the tendency of heat conduction may moreincrease and act as a larger factor that deteriorates the heatconduction resistance performance of the vacuum adiabatic body.

Hereinafter, the outer area of the radiation resistance sheet 32 will bedescribed in more detail. Particularly, the supporting unit 30 appliedto the main body 2 will be described as an example, but it is notexcluded that the idea is applied to the door 3.

First, since the radiation resistance sheet 32 has the edge area, andthe edge area is not supported, the radiation resistance sheet 32 may befreely deformed by the external impact. The deformation may be limitedby strength of the radiation resistance sheet 32, but it is vulnerableto deformation because it is processed to a considerably thin shape.

A process in which the supporting unit is inserted into the vacuuminsertion part 50 will be described.

FIGS. 9 to 12 are schematic cross-sectional views of the vacuumadiabatic body into which the supporting unit is inserted.

As illustrated in FIG. 9, the second plate member 20 is prepared. Thesecond plate member 20 may provide a wall of a second space that is anexternal space, i.e., a room-temperature space.

Thereafter, as illustrated in FIG. 10, any one supporting unit 30 isinserted into a bottom surface of the second plate member 20. Thesupport unit 30 may be exemplified to include the support plates 35 and36, the bar 31, and a structure supporting a position of the radiationresistance sheet 32.

Thereafter, as illustrated in FIG. 11, the supporting unit 30 isinserted into an inner sidewall of the second plate member 20. An end ofthe supporting unit 30 disposed on one outer surface of the supportplates 35 and 36 is disposed on the supporting unit 30 disposed on thebottom surface. That is, the support unit 30 disposed on the sidesurface is placed on the supporting unit 30 disposed on the bottomsurface.

Thereafter, as illustrated in FIG. 12, the first plate member 10 isinserted. Before the first plate member 10 is inserted, the supportingunit 30 may be temporally assembled. When the first plate member 10 isinserted, the whole structure including the supporting unit 30 may bestable in position. Then, the vacuum space part 50 is sealed by theconductive resistance sheet 60.

Thereafter, an action of exhaust and gettering (or depressurization) maybe further performed.

FIG. 13 is schematic cross-sectional view of the supporting unit.

Referring to FIG. 13, according to this embodiment, the support plates35 and 36 may further extend to the outside of the edge area of theradiation resistance sheet 32. That is, the edge area of the radiationresistance sheet 32 may be disposed inside an edge of each of thesupport plates 35 and 36. When viewed in a cross-section, an edge of theradiation resistance sheet 32 may be disposed inside a virtual line (adotted line in FIG. 13) connecting the edges of the pair of radiationresistance sheets 32 to each other.

According to the above-described constituents, the radiation resistancesheet 32 may not come into contact with other parts within the vacuumspace part 50. The radiation resistance sheet 32 may not come intocontact with the other support unit 30 that is adjacent thereto. Thus,the adiabatic performance of the vacuum adiabatic body may be improved,and the deterioration in adiabatic performance due to use for a longtime may be prevented.

A process in which the supporting unit is inserted into the vacuuminsertion part according to another embodiment will be described.

FIGS. 14 to 17 are schematic cross-sectional views of a vacuum adiabaticbody into which a supporting unit is inserted according to anotherembodiment, and FIG. 18 is schematic cross-sectional view of thesupporting unit according to another embodiment.

Referring to FIG. 18, support plates 35 and 36 are divided into twoparts different from each other. For example, the support plates 35 and36 may be divided into a first support plate 35 disposed inside a mainbody and a second support plate 36 disposed outside the main body 2. Inother aspect, the support plates 35 and 36 may be divided into a secondsupport plate 36 coming into contact with a vacuum adiabatic body and afirst support plate 35 that does not come into contact with the vacuumadiabatic body.

In this case, an edge of a radiation resistance sheet 32 may bepositioned inside a virtual line connecting the edges of the first andsecond support plates 35 and 36. Thus, the radiation resistance sheet 32may not come into contact with the other support unit 30 that isadjacent thereto. Thus, the adiabatic performance of the vacuumadiabatic body may be improved, and the deterioration in adiabaticperformance due to use for a long time may be prevented.

The first support plate 35 may have a size less than that of the secondsupport plate 36. When the main body 2 is provided, the use of othertypes of supporting units 30 may lead to an increase in inventory ratioand complicated process problems. To solve these problems, it ispossible to process the supporting unit 30 in the same shape, inparticular, the parts coming into contact with the supporting units 30in the same shape so that the parts coming into contact with each othermay be aligned with each. For this, the virtual line connecting theedges of the first and second support plates 35 and 36 to each other maybe provided at an angle of about 45 degrees with respect to a verticalline connecting the support plates 35 and 36 to each other.

When the mounting of the support unit is successively described, asillustrated in FIG. 14, the second plate member 20 is prepared. Thesecond plate member 20 may provide a wall of a second space that is anexternal space.

Thereafter, as illustrated in FIG. 15, any one supporting unit 30 isinserted into a bottom surface of the second plate member 20. Thesupporting unit 30 may come into contact with the second support plate36, and the first support plate 35 may be directed to the inside of themain body. Alternatively, the support unit 30 may include the radiationresistance sheet 32, the bar 31, and a structure supporting a positionof the radiation resistance sheet 32.

Thereafter, as illustrated in FIG. 16, the supporting unit 30 isinserted into an inner sidewall of the second plate member 20. When allthe supporting units 30 are inserted, the support unit 30 disposed onthe bottom surface and the supporting unit 30 disposed on the sidesurface may come into contact with each other. Here, the supportingunits 30 coming into contact with each other may be configured so thatthe support plates 35 come into contact with each other, and theradiation resistance sheets 32 do not come into contact with each other.Thus, the adiabatic performance may be improved.

Thereafter, as illustrated in FIG. 17, the first plate member 10 isinserted. Before the first plate member 10 is inserted, the supportingunit 30 may be temporally assembled. When the first plate member 10 isinserted, the whole structure including the supporting unit 30 may bestable in position. Then, the vacuum space part 50 is sealed by theconductive resistance sheet 60.

Thereafter, an action of exhaust and gettering may be further performed.

FIG. 19 is an enlarged perspective view illustrating a contact part ofthe supporting unit.

Referring to FIG. 19, in the drawing, a vertical supporting unit is amember that is placed on a bottom wall of the main body 2, and ahorizontal supporting unit is a member placed on a sidewall of the mainbody 2. When observing edge parts of the support plates 35 and 36, it isseen that an end of the supporting unit disposed on the side surface isplaced on the supporting unit disposed on the bottom surface.

In detail, an end of the second support plate 302 of the supporting unitdisposed on the side surface may be placed on the second support plate301 of the supporting unit disposed on the bottom surface. According tothe above-described constituents, the supporting unit 30 on the bottomsurface may cover the bottom surface of the second plate member 20 as awhole, so that the assembly is convenient. Here, a space therebetweenallows for engineering assembly tolerances for insertion, but may notallow other members to be inserted therebetween. That is, an edge of thesecond support plate 301 of the supporting unit 30 on the bottom surfacemay be manufactured through the same process as an inner area of thesecond plate member 20.

In this case, it is seen that an edge of the radiation resistance sheet32 is disposed inside a virtual line (see a dotted line) connectingedges of the first and second support plates 35 and 36 to each other ineach of the supporting units 30. Thus, it is possible to prevent theproblem that the radiation resistance sheet comes into contact with theradiation resistance sheet 32 of another adjoining supporting unit atthe time of installing the supporting unit 30. Furthermore, even whenthe radiation resistance sheet 32 is curved to a certain degree due toan external impact, there is no problem of coming into contact withother products in the vacuum space part 50, thereby improving the heatadiabatic performance of the vacuum adiabatic body.

When a strong impact is applied to the radiation resistance sheet 32,the radiation resistance sheet 32 may be bent to a considerable level,for example, a level exceeding about 40 degrees. Such a problem mayoccur if the foil is provided in an extremely thin plate shape.

A description will be given of the position at which a bent angle of theradiation resistance sheet 32 may occur at a considerable level or more,for example, the edge part of the radiation resistance sheet 32 usablein the vehicle or the portable refrigerator.

FIG. 20 is a schematic view illustrating an edge part of the supportingunit.

Referring to FIG. 20, the supporting unit include the first supportplate 35, the second support plate 36, the bar 31 supporting the spacingpart between the support plates 35 and 36, and the radiation resistancesheet 32 fixed to the bar 31.

The radiation resistance sheet 32 may be supported in position by usingthe bar 31 as a supporting point, and the outside of the radiationresistance sheet 32 may be bent or deformed by an external impact as anedge area.

In order to prevent such bending and deformation from affecting thedeterioration of the adiabatic performance, which is caused by theradiation resistance sheet 32, a distance I2 from the supporting pointto the edge of the radiation resistance sheet 32 is provided to beshorter than a distance I1 to the virtual line connecting the edges ofthe first and second support plates 35 and 36 to each other at thesupporting point. Thus, the radiation resistance sheets of the differentsupporting units 30 adjacent to each other may not come into contactwith each other. The distance I2 from the supporting point to the edgeof the radiation resistance sheet 32 may range from about 10 mm to about15 mm.

When an end of the supporting unit 30 is provided to be verticallyinclined, a process in which the supporting unit is inserted into thevacuum insertion part 50 according to another embodiment will bedescribed.

FIGS. 21 to 24 are schematic cross-sectional views of a vacuum adiabaticbody into which a supporting unit is inserted according to anotherembodiment.

As illustrated in FIG. 21, a second plate member 20 is prepared. Thesecond plate member 20 may provide a wall of a second space that is anexternal space.

Thereafter, as illustrated in FIG. 22, a supporting unit 30 is insertedinto a side surface of the second plate member 20. The support unit 300may be exemplified to include support plates 35 and 36, radiationresistance sheet 32, a bar 31, and a structure supporting a position ofthe radiation resistance sheet 32. The supporting unit 30 disposed onthe side surface may be supported in position by a predetermined jig.

Thereafter, as illustrated in FIG. 23, the supporting unit 30 isinserted into a bottom surface of the second plate member 20. An end ofthe supporting unit 30 disposed on the bottom surface of one outersurface of the support plates 35 and 36 is disposed on the supportingunit 30 disposed on the side surface. That is, the support unit 30disposed on the bottom surface is placed on the supporting unit 30disposed on the side surface.

Thereafter, as illustrated in FIG. 24, the first plate member 10 isinserted. Before the first plate member 10 is inserted, the supportingunits 30 may be temporally assembled. When the first plate member 10 isinserted, the whole structure including the supporting unit 30 may bestable in position. Then, the vacuum space part 50 is sealed by theconductive resistance sheet 60.

Thereafter, an action of exhaust and gettering may be further performed.

Even in this case, the supporting unit 30 may have the same structureand shape as that of FIG. 13 except for a size of the supporting unit30.

Hereinafter, a vacuum pressure preferably determined depending on aninternal state of the vacuum adiabatic body. As already described above,a vacuum pressure is to be maintained inside the vacuum adiabatic bodyso as to reduce heat transfer. At this time, it will be easily expectedthat the vacuum pressure is preferably maintained as low as possible soas to reduce the heat transfer.

The vacuum space part may resist the heat transfer by applying only thesupporting unit 30. Alternatively, the porous substance 33 may be filledtogether with the supporting unit in the vacuum space part 50 to resistthe heat transfer. Alternatively, the vacuum space part may resist theheat transfer not by applying the supporting unit but by applying theporous substance 33.

The case where only the supporting unit is applied will be described.

FIG. 25 illustrates graphs showing changes in adiabatic performance andchanges in gas conductivity with respect to vacuum pressures by applyinga simulation.

Referring to FIG. 25, it may be seen that, as the vacuum pressure isdecreased, i.e., as the vacuum degree is increased, a heat load in thecase of only the main body (Graph 1) or in the case where the main bodyand the door are joined together (Graph 2) is decreased as compared withthat in the case of the typical product formed by foaming polyurethane,thereby improving the adiabatic performance. However, it may be seenthat the degree of improvement of the adiabatic performance is graduallylowered. Also, it may be seen that, as the vacuum pressure is decreased,the gas conductivity (Graph 3) is decreased. However, it may be seenthat, although the vacuum pressure is decreased, the ratio at which theadiabatic performance and the gas conductivity are improved is graduallylowered. Therefore, it is preferable that the vacuum pressure isdecreased as low as possible. However, it takes a long time to obtainexcessive vacuum pressure, and much cost is consumed due to excessiveuse of a getter. In the embodiment, an optimal vacuum pressure isproposed from the above-described point of view.

FIG. 26 illustrates graphs obtained by observing, over time andpressure, a process of exhausting the interior of the vacuum adiabaticbody when the supporting unit is used.

Referring to FIG. 26, in order to create the vacuum space part 50 to bein the vacuum state, a gas in the vacuum space part 50 is exhausted by avacuum pump while evaporating a latent gas remaining in the parts of thevacuum space part 50 through baking. However, if the vacuum pressurereaches a certain level or more, there exists a point at which the levelof the vacuum pressure is not increased any more (Δt1). After that, thegetter is activated by disconnecting the vacuum space part 50 from thevacuum pump and applying heat to the vacuum space part 50 (Δt2). If thegetter is activated, the pressure in the vacuum space part 50 isdecreased for a certain period of time, but then normalized to maintaina vacuum pressure of a certain level. The vacuum pressure that maintainsthe certain level after the activation of the getter is approximately1.8×10−6 Torr.

In the embodiment, a point at which the vacuum pressure is notsubstantially decreased any more even though the gas is exhausted byoperating the vacuum pump is set to the lowest limit of the vacuumpressure used in the vacuum adiabatic body, thereby setting the minimuminternal pressure of the vacuum space part 50 to 1.8×10−6 Torr.

FIG. 27 illustrates graphs obtained by comparing vacuum pressures andgas conductivities.

Referring to FIG. 27, gas conductivities with respect to vacuumpressures depending on sizes of a gap in the vacuum space part 50 arerepresented as graphs of effective heat transfer coefficients (eK).Effective heat transfer coefficients (eK) were measured when the gap inthe vacuum space part 50 has three sizes of 2.76 mm, 6.5 mm, and 12.5mm. The gap in the vacuum space part 50 is defined as follows. When theradiation resistance sheet 32 exists inside vacuum space part 50, thegap is a distance between the radiation resistance sheet 32 and theplate member adjacent thereto. When the radiation resistance sheet 32does not exist inside vacuum space part 50, the gap is a distancebetween the first and second plate members.

It may be seen that, since the size of the gap is small at a pointcorresponding to a typical effective heat transfer coefficient of 0.0196W/mK, which is provided to a adiabatic material formed by foamingpolyurethane, the vacuum pressure is 2.65×10−1 Torr even when the sizeof the gap is 2.76 mm. Meanwhile, it may be seen that the point at whichreduction in adiabatic effect caused by gas conduction heat is saturatedeven though the vacuum pressure is decreased is a point at which thevacuum pressure is approximately 4.5×10−3 Torr. The vacuum pressure of4.5×10−3 Torr may be defined as the point at which the reduction inadiabatic effect caused by gas conduction heat is saturated. Also, whenthe effective heat transfer coefficient is 0.1 W/mK, the vacuum pressureis 1.2×10−2 Torr.

When the vacuum space part 50 is not provided with the supporting unitbut provided with the porous substance, the size of the gap ranges froma few micrometers to a few hundreds of micrometers. In this case, theamount of radiation heat transfer is small due to the porous substanceeven when the vacuum pressure is relatively high, i.e., when the vacuumdegree is low. Therefore, an appropriate vacuum pump is used to adjustthe vacuum pressure. The vacuum pressure appropriate to thecorresponding vacuum pump is approximately 2.0×10−4 Torr. Also, thevacuum pressure at the point at which the reduction in adiabatic effectcaused by gas conduction heat is saturated is approximately 4.7×10−2Torr. Also, the pressure where the reduction in adiabatic effect causedby gas conduction heat reaches the typical effective heat transfercoefficient of 0.0196 W/mK is 730 Torr.

When the supporting unit and the porous substance are provided togetherin the vacuum space part, a vacuum pressure may be created and used,which is middle between the vacuum pressure when only the supportingunit is used and the vacuum pressure when only the porous substance isused.

In the description of the present disclosure, a part for performing thesame action in each embodiment of the vacuum adiabatic body may beapplied to another embodiment by properly changing the shape ordimension of another embodiment. Accordingly, still another embodimentmay be easily proposed. For example, in the detailed description, in thecase of a vacuum adiabatic body suitable as a door-side vacuum adiabaticbody, the vacuum adiabatic body may be applied as a main body-sidevacuum adiabatic body by properly changing the shape and configurationof a vacuum adiabatic body.

The vacuum adiabatic body proposed in the present disclosure may bepreferably applied to refrigerators. However, the application of thevacuum adiabatic body is not limited to the refrigerators, and may beapplied in various apparatuses such as cryogenic refrigeratingapparatuses, heating apparatuses, and ventilation apparatuses.

INDUSTRIAL APPLICABILITY

According to the present disclosure, the vacuum adiabatic body may beindustrially applied to various adiabatic apparatuses. The adiabaticeffect may be enhanced, so that it is possible to improve energy useefficiency and to increase the effective volume of an apparatus.

The invention claimed is:
 1. A vacuum adiabatic body comprising: a firstplate; a second plate spaced apart from the first plate to form a spacetherebetween, wherein the first and second plates are configured to besealed such that the space is a vacuum space; at least one support plateprovided adjacent to at least one of the first plate or the secondplate; at least one first pillar provided between the first and secondplates; at least one radiation resistance sheet provided between thefirst plate and the second plate to reduce heat transfer between thefirst plate and the second plate; at least one first hole provided inthe radiation resistance sheet and through which the at least one firstpillar passes, the first hole being configured to guide a position ofthe radiation resistance sheet within the space, and the at least onefirst hole and the at least one first pillar supporting a horizontalmovement of the radiation resistance sheet; and a spacing block providedbetween the radiation resistance sheet and the support plate.
 2. Thevacuum adiabatic body of claim 1, wherein a distance between an inneredge of the first hole and the first pillar is in a range of 0.1 mm to0.5 mm.
 3. The vacuum adiabatic body of claim 1, wherein the first holeis provided at an outer side of the radiation resistance sheet.
 4. Thevacuum adiabatic body of claim 1, wherein the radiation resistance sheetdoes not contact the first pillar.
 5. The vacuum adiabatic body of claim1, wherein an inner area of the radiation resistance sheet is maintainedat a horizontal position by the first pillar and the first hole, andmaintained in a vertical position by the spacing block.
 6. The vacuumadiabatic body of claim 1, wherein the at least one radiation resistancesheet includes at least two radiation resistance sheets, and a secondaryspacing block is provided between the radiation resistance sheets. 7.The vacuum adiabatic body of claim 1, wherein the radiation resistancesheet includes an edge area which is not supported by the at least onefirst pillar and is provided outside of the first hole.
 8. A fabricationmethod for a vacuum adiabatic body, comprising: preparing a first plateincluding a first bottom wall and a first side wall; inserting aplurality of supports, an outer side of each of the plurality ofsupports corresponding to an inner side of the first bottom wall and aninner side of the first side wall; inserting a second plate including asecond bottom wall and a second side wall, wherein an inner side of eachof the plurality of supports corresponds to an inner side of the secondbottom wall and an inner side of the second side wall, the inner sidesof the second bottom wall and the second side wall being sides facingthe first bottom wall and the first side wall, respectively; sealing aninner space between the first plate and the second plate by a conductiveresistance sheet, the conductive resistance sheet connect an edge of thefirst plate and an edge of the second plate; and exhausting the innerspace.
 9. The fabrication method for a vacuum adiabatic body of theclaim 8, wherein the plurality of supports includes a first supportcorresponding to the first side wall and a second support correspondingto the first bottom wall, wherein each of the first and second supportsincludes a support plate, a pillar configured to maintain a distancebetween the first plate and the second plate, and a radiation sheetprovided between the first plate and the second plate to reduce heattransfer between the first plate and the second plate, and wherein anedge of the support plate extends past an edge of the radiationresistance sheet.
 10. The fabrication method for a vacuum adiabatic bodyof the claim 8, wherein the plurality of supports includes a firstsupport corresponding to the first side wall and a second supportcorresponding to the first bottom wall, the first support being insertedafter the second support, wherein each of the first and second supportsincludes a support plate, a pillar configured to maintain a distancebetween the first plate and the second plate, and a radiation sheetprovided between the first plate and the second plate to reduce heattransfer between the first plate and the second plate, and wherein anedge of the radiation resistance sheet is extends past an edge of thesupport plate.
 11. A vacuum adiabatic body, comprising: a first plate; asecond plate spaced apart from the first plate to form a spacetherebetween, wherein the first and second plates are configured to besealed such that the space is a vacuum space; a first support platesupported by the first plate or the second plate; a plurality of pillarsconfigured to maintain a distance between the first plate and the secondplate; at least one radiation resistance sheet provided between thefirst plate and the second plate to reduce heat transfer between thefirst plate and the second plate; and a plurality of holes through whichthe plurality of pillars passes, respectively, the plurality of holesbeing configured to guide a position of the radiation resistance sheetwithin the space, wherein the radiation resistance sheet includes anedge that extends past an edge of the first support plate.
 12. Thevacuum adiabatic body of the claim 11, further comprising a secondsupport plate, the second support plate extending past the edge of theradiation resistance sheet.
 13. The vacuum adiabatic body of the claim12, wherein a virtual line between an edge of the first support plateand an edge of the second support plate is inclined with respect to anextension direction of the first and second support plates, wherein adistance from a supporting point at which an outmost pillar of theplurality of pillars supports the radiation resistance sheet to the edgeof the radiation resistance sheet is less than a distance from thesupporting point to the virtual line.
 14. A vacuum adiabatic bodycomprising: a first plate; a second plate spaced apart from the firstplate to form a space therebetween, wherein the first and second platesare configured to be sealed such that the space is a vacuum space; atleast one support plate provided adjacent to at least one of the firstplate or the second plate; at least one first pillar provided betweenthe first and second plates; at least one radiation resistance sheetprovided between the first plate and the second plate; at least onefirst hole provided in the radiation resistance sheet through which theat least one first pillar passes, the first hole being configured toguide a position of the radiation resistance sheet within the space; anda spacing block provided between the radiation resistance sheet and thesupport plate; wherein a distance between an inner edge of the spacingblock and the first pillar is greater than a distance between the inneredge of the first hole and the first pillar.
 15. A vacuum adiabatic bodycomprising: a first plate; a second plate spaced apart from the firstplate to form a space therebetween, wherein the first and second platesare configured to be sealed such that the space is a vacuum space; atleast one support plate provided adjacent to at least one of the firstplate or the second plate; at least one first pillar provided betweenthe first and second plates; at least one radiation resistance sheetprovided between the first plate and the second; at least one first holeprovided in the radiation resistance sheet through which the at leastone first pillar passes, the first hole being configured to guide aposition of the radiation resistance sheet within the space; a spacingblock provided between the radiation resistance sheet and the supportplate; and at least one second pillar and at least one second holethrough which the at least one second pillar passes, wherein the secondhole is larger than the first hole.
 16. The vacuum adiabatic body ofclaim 15, wherein a distance between an inner edge of the second holeand the second pillar is in a range of 0.3 mm to 1.5 mm, or wherein adistance between an inner edge of the spacing block and the secondpillar is greater than the distance between the inner edge of the secondhole and the second pillar.
 17. The vacuum adiabatic body of claim 15,wherein the at least one first hole includes at least two first holes,and the second hole is provided between the two first holes.
 18. Thevacuum adiabatic body of claim 17, wherein a distance between adjacentholes of the at least two first holes is less than 200 mm, or whereinthe at least one second hole includes at least two second holes, and anumber of the first holes is less than a number of the second holes.